A. Field of the Invention
This relates to detecting areas of corrosion on vessels or containers, particularly vessels and containers that carry caustic or harmful materials.
B. Prior Art
There are many other prior art references to the testing of tanks and containers with regard to areas of corrosion and all types of corrosion.
One of them may be found at Marchal, U.S. Pat. No. 6,960,288, which is a method and device for detecting microbiologically induced corrosion. This reference uses an electrode through which an electrical current is passed to detect the presence of corrosion. It does not use a camera.
Another method to nondestructively test for or detect material abnormalities beneath a coated surface can be found at Alfano, U.S. Pat. No. 6,853,926. The Alfano reference uses a light source to detect infrared rays.
Still other patents test for corrosion using ultrasonic waves such as found at Gorman, U.S. Pat. No. 6,595,061 Gorman, U.S. Pat. No. 6,595,059 and Gorman, U.S. Pat. No. 6,363,788. All three Gorman references use ultrasonic waves to detect the presence of corrosion. None of the Gorman references use a color camera or compile the information using a histogram.
Other patents related to the nondestructive detection of steel surfaces include Perez, U.S. Pat. No. 5,646,400, which uses an embedded optical fiber. Light is transmitted through the embedded fiber and analysis of the refracted light alerts the operator to the presence of possible areas of corrosion.
With the current method and apparatus a color camera is used to take a video image of the surface of the container. This image is integrated into software, which tests for certain surface characteristics on the tank lining or exterior surface to detect the presence of corrosion. This method can be used to test for any type of corrosion and does not use ultrasonic waves or the other means to test that is found in the prior art.